BRUSSELS (AP) — The European Union suspects that damage to two underwater natural gas pipelines was sabotage and is warning of retaliation for any attack on Europe’s energy networks, EU foreign policy chief Josep Borrell said Wednesday.

“All available information indicates those leaks are the result of a deliberate act,” Borrell said in a statement on behalf of the 27 EU member countries. “Any deliberate disruption of European energy infrastructure is utterly unacceptable and will be met with a robust and united response.”

Seismologists reported Tuesday that explosions rattled the Baltic Sea before unusual leaks were discovered on two underwater natural gas pipelines running from Russia to Germany.